Mobility management has become an important feature of mobile communication networks. For this reason, several mobility management standards have evolved over the last years.
One standardized mobility management protocol is the General Packet Radio Service (GPRS) tunneling protocol (GTP). GTP is an Internet protocol (IP) based network protocol used within Third Generation Partnership Project (3GPP) networks such as Universal Mobile Telecommunications System (UMTS) networks. GTP is used for mobility management over the roaming interfaces of 3GPP networks. In addition to mobility management, GTP provides session management, bearer control for Quality of Service (QoS) and other network functions. GTP is described in document 3GPP TS 29.060, “Third Generation Partnership Project, Technical Specification Group Core Network and Terminals; General Packet Radio Service (GPRS); GPRS Tunneling Protocol (GTP) across the Gn and GP interface (Release 8)” in detail.
Another standardized mobility management protocol is Mobile IPv6 (MIPv6). MIPv6 is a generic mobility protocol which allows a mobile terminal to transparently maintain network connections while moving from one subnet to another. In MIPv6, mobile terminals are authenticated by means of IPv6 addresses. MIPv6 provides direct routing between IPv6 correspondent nodes (CN) and mobile terminals for optimizing the flow of network traffic. This direct routing is described in document “Mobility support in IPv6”, RFC 3775 by the Internet Engineering Task Force (IETF).
Other IETF protocols enabling a host to receive traffic through multiple points of attachment, such as the Level 3 Multihoming Shim Protocol for IPv6 (shim6) or the Host Identity Protocol (HIP), are known as well.
Shim6 specifies a layer 3 shim protocol for providing locator agility below the transport protocols. Thereby, multihoming for IPv6 can be provided with failover and load spreading properties. Shim6 is described in document “Level 3 multihoming shim protocol for IPv6”, internet draft, draft-IETF-shim-6-proto-07.text by IETF.
HIP provides a method of separating the end-point identifier and locator rolls of IP addresses and introduces a new host identity name space. The host identity protocol is described in document “Host Identity Protocol (HIP) architecture”, RFC 4423 by IETF.
Network protocols like GTP, MIPv6, shim6 and HIP comprise distinctive mobility features. However, they also lack important network management features which other protocols support.
For example, GTP is embedded into the 3GPP architecture and provides QoS and bearer control features, but does not support route optimization of network traffic. However, route optimization may be useful to avoid so called “triangle routing”. Triangle routing concerns the situation that a mobile terminal wants to send data packets to another mobile terminal within the same network. However, the other mobile terminal may be located far away from its home network. Since no direct path is provided by means of route optimization, the data packets are tunneled through the network in order to reach the home agent and are subsequently tunneled back across the network to reach the foreign agent. Thereby, network capacity is unnecessarily occupied.
On the other hand, MIPv6 supports route optimization. However, MIPv6 lacks the ability to provide bearer control for QoS. Moreover, MIPv6 is not embedded into the 3GPP architecture. However, most worldwide network operators operate and are expanding in networks according to the 3GPP standards.
Shim6 and HIP provide a possibility of communicating via CNs by using a direct path. However, similar to MIPv6, shim6 and HIP lack QoS and bearer control features.